Another vote for the Janome 6600. I have had mine for 10 years and never have had any problems. Made so many quilts that I have lost count, not to mention all the other sewing I have done. It has lots of features that make sewing/quilting a breeze. It weighs about 25 lbs which is easy enough to move around. I take it to retreats, classes, etc. but I have a rolling cart to carry it in.
Janome just came out with a 6700 which is an "upgrade" to the 6600 and you may find a bargain on the 6600.
I suggest you go to the Janome website and see all the features this machine has as well as others. Don't be put off by the MSRP listing, bargains can be found and deals made. Good luck in your search and with your new machine!
here is a link to a discussion on this board on the 6600 last August.
Janome 6600P
Murphy